One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,7)(3,5,8,6)(10,15)(12,13)(16,23)(17,21)(18,19)(22,24)(26,31)(27,34)(28,29)(33,36)(35,37)(38,39)(9,10,14,17)(11,16,20,24)(12,15,13,21)(18,23,19,22)(25,26)(27,32)(28,36)(29,31)(30,33)(34,39)(35,40)(37,38)(2,5)(3,8)(6,7)(9,11,14,20)(10,16,17,24)(12,19,13,18)(15,22,21,23)(25,27,30,35)(26,32,33,40)(28,34,29,37)(31,38,36,39)(9,12,14,13)(10,15,17,21)(11,18,20,19)(16,23,24,22)(26,33)(27,35)(31,36)(34,37)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.